{"source":"PHIVOLCS Active Faults and Trenches Map (2015) and related open-file reports — simplified for display.","attribution":"Philippine Institute of Volcanology and Seismology (PHIVOLCS-DOST)","count":21,"faults":[{"slug":"philippine-fault-zone","name":"Philippine Fault Zone","type":"strike-slip","length_km":1200,"slip_rate_mm_yr":"20–25","region":"Luzon → Eastern Visayas → Mindanao","description":"A ~1,200 km left-lateral strike-slip fault traversing the archipelago, accommodating oblique convergence between the Philippine Sea Plate and Sunda Block.","notable_events":["1990 M7.8 Luzon earthquake (Digdig segment)","2003 M6.2 Masbate"],"source":"PHIVOLCS Active Faults and Trenches Map (2015)","geometry":[[122,18.4],[121.5,17],[121,15.5],[122,13.5],[124,12.5],[125,10.5],[125.5,8.5],[126,7]]},{"slug":"valley-fault-system","name":"Valley Fault System (West & East Valley Faults)","type":"strike-slip","length_km":100,"slip_rate_mm_yr":"~3–5","region":"Metro Manila, Rizal, Bulacan, Cavite, Laguna","description":"Right-lateral strike-slip system bounding the Marikina Valley. The West Valley Fault is capable of generating a ~M7.2 event ('The Big One' scenario).","notable_events":["Last major rupture: ~1658 (paleoseismic)"],"source":"PHIVOLCS Valley Fault System Atlas (2015)","geometry":[[121.08,14.85],[121.07,14.7],[121.06,14.55],[121.08,14.4],[121.1,14.2]]},{"slug":"manila-trench","name":"Manila Trench","type":"subduction","length_km":1000,"slip_rate_mm_yr":"~50–80 convergence","region":"Western Luzon margin","description":"East-dipping subduction zone where the South China Sea (Sunda) plate subducts beneath Luzon. A significant tsunami source for the South China Sea region.","notable_events":["Multiple M7+ historical events"],"source":"PHIVOLCS / global subduction zone catalogs","geometry":[[119.5,19],[119.2,17],[119,15],[119.3,13]]},{"slug":"philippine-trench","name":"Philippine Trench","type":"subduction","length_km":1320,"slip_rate_mm_yr":"~50–70 convergence","region":"Eastern Philippine margin","description":"West-dipping subduction zone where the Philippine Sea Plate underthrusts the archipelago. Source of major deep events along eastern Mindanao and Samar.","notable_events":["2012 M7.6 Samar","2023 M7.6 Hinatuan, Surigao del Sur"],"source":"PHIVOLCS / USGS Slab2","geometry":[[127.5,16.5],[127,13],[126.5,10],[126.5,7],[126.8,5.5]]},{"slug":"cotabato-trench","name":"Cotabato Trench","type":"subduction","length_km":300,"slip_rate_mm_yr":"~30","region":"Southwestern Mindanao","description":"Short subduction zone offshore western Mindanao, source of the destructive 1976 Moro Gulf earthquake and tsunami.","notable_events":["1976 M7.9 Moro Gulf (tsunami, 5,000+ casualties)"],"source":"PHIVOLCS Destructive Earthquakes Catalog","geometry":[[123,7.5],[122.5,6.5],[122,5.5]]},{"slug":"negros-trench","name":"Negros Trench","type":"subduction","length_km":350,"region":"Western Visayas (Negros, Panay)","description":"East-dipping subduction zone west of Negros and Panay.","notable_events":["2012 M6.7 Negros Oriental"],"source":"PHIVOLCS","geometry":[[122.5,11.5],[122.3,10],[122,9]]},{"slug":"central-cebu-fault","name":"Central Cebu Fault System","type":"strike-slip","length_km":100,"region":"Cebu Island","description":"North–south trending strike-slip system traversing central Cebu. Considered capable of generating destructive shallow earthquakes affecting Metro Cebu.","notable_events":["Background seismicity; no recent surface-rupturing event documented"],"source":"PHIVOLCS Active Faults and Trenches Map (2015)","geometry":[[123.95,10.95],[123.85,10.5],[123.7,10.1],[123.6,9.7]]},{"slug":"north-bohol-fault","name":"North Bohol Fault","type":"thrust","length_km":6,"region":"Bohol","description":"Previously unmapped reverse fault identified after the 2013 M7.2 Bohol earthquake. Produced surface rupture across northern Bohol.","notable_events":["2013 M7.2 Bohol earthquake (~220 casualties)"],"source":"PHIVOLCS Quick Response Team report (2013)","geometry":[[124,9.95],[124.05,9.93],[124.1,9.92]]},{"slug":"lubang-fault","name":"Lubang Fault","type":"strike-slip","length_km":220,"region":"Verde Island Passage, Mindoro, Batangas","description":"Left-lateral strike-slip fault offshore Lubang and Mindoro. Source of the 1994 M7.1 Mindoro earthquake and tsunami.","notable_events":["1994 M7.1 Mindoro (Aglubang) earthquake and tsunami"],"source":"PHIVOLCS; Imamura et al. 1995","geometry":[[120,13.85],[120.5,13.6],[121,13.4],[121.5,13.2]]},{"slug":"east-luzon-trough","name":"East Luzon Trough","type":"trench","length_km":400,"region":"Eastern Luzon offshore","description":"Bathymetric trough offshore eastern Luzon, considered a possible incipient subduction zone north of the Philippine Trench.","notable_events":["Background offshore seismicity"],"source":"PHIVOLCS / Hamburger et al. 1983","geometry":[[123,18],[123.2,16.5],[123.5,15]]},{"slug":"sulu-trench","name":"Sulu Trench","type":"subduction","length_km":250,"region":"Sulu Sea","description":"Subduction zone where the Sulu Sea Basin underthrusts the Sulu Archipelago.","notable_events":["Background deep seismicity"],"source":"PHIVOLCS","geometry":[[120.5,7.5],[121,6.5],[121.5,5.5]]},{"slug":"digdig-fault","name":"Digdig Fault (PFZ Central Luzon segment)","type":"strike-slip","length_km":220,"slip_rate_mm_yr":"~20","region":"Nueva Ecija, Nueva Vizcaya, Aurora","description":"Northern segment of the Philippine Fault Zone in Central Luzon. Ruptured during the 1990 M7.8 Luzon earthquake with surface displacement of up to 6 m left-laterally over >120 km.","notable_events":["1990 M7.8 Luzon earthquake"],"source":"Nakata et al. 1996; PHIVOLCS Active Faults Map (2015)","geometry":[[121.05,16.4],[121.15,15.9],[121.25,15.6],[121.35,15.3],[121.4,15]]},{"slug":"guinayangan-fault","name":"Guinayangan Fault (PFZ Bondoc segment)","type":"strike-slip","length_km":180,"slip_rate_mm_yr":"~20","region":"Quezon, Camarines Norte","description":"Bondoc Peninsula segment of the Philippine Fault Zone, connecting the Sibuyan Sea segment to the Ragay Gulf segment.","notable_events":["1973 M7.0 Ragay Gulf earthquake (75 casualties)"],"source":"PHIVOLCS Active Faults Map (2015)","geometry":[[122,13.8],[122.4,13.5],[122.8,13.2],[123.2,13]]},{"slug":"masbate-fault","name":"Masbate Fault (PFZ Masbate segment)","type":"strike-slip","length_km":110,"slip_rate_mm_yr":"~25","region":"Masbate Island","description":"Onshore segment of the Philippine Fault Zone crossing Masbate Island. Ruptured during the 2003 M6.2 Masbate earthquake.","notable_events":["2003 M6.2 Masbate earthquake"],"source":"Bacolcol et al. 2005; PHIVOLCS","geometry":[[123.2,12.6],[123.5,12.3],[123.8,12],[124,11.8]]},{"slug":"leyte-fault","name":"Leyte Fault (PFZ Leyte segment)","type":"strike-slip","length_km":270,"slip_rate_mm_yr":"~25–30","region":"Leyte, Southern Leyte","description":"Onshore left-lateral strike-slip segment of the Philippine Fault Zone traversing Leyte. Source of the 2017 M6.5 Leyte earthquake.","notable_events":["2017 M6.5 Leyte earthquake","2003 Saint Bernard landslide complex"],"source":"PHIVOLCS Active Faults Map (2015)","geometry":[[124.5,11.5],[124.8,11],[125,10.5],[125.2,10]]},{"slug":"mindanao-fault","name":"Mindanao Fault (PFZ Mindanao segment)","type":"strike-slip","length_km":320,"slip_rate_mm_yr":"~25","region":"Agusan, Davao, Compostela Valley","description":"Southern onshore segment of the Philippine Fault Zone across Mindanao, from Agusan through the Davao region.","notable_events":["Background M5–6 seismicity along trace"],"source":"PHIVOLCS Active Faults Map (2015)","geometry":[[125.5,9],[125.8,8],[126,7],[126.1,6.2]]},{"slug":"vigan-aggao-fault","name":"Vigan–Aggao Fault","type":"strike-slip","length_km":150,"region":"Ilocos Sur, Abra","description":"NW-trending strike-slip system in northwest Luzon, intersecting the Philippine Fault Zone. Consistent with the source kinematics of the 2022 M7.0 Abra earthquake.","notable_events":["2022 M7.0 Abra earthquake"],"source":"PHIVOLCS Quick Response Team 2022","geometry":[[120.5,17.9],[120.7,17.6],[120.9,17.3],[121,17]]},{"slug":"casiguran-fault","name":"Casiguran Fault","type":"thrust","length_km":80,"region":"Aurora","description":"Reverse fault offshore Aurora that ruptured during the 1968 M7.6 Casiguran earthquake, which damaged Manila (Ruby Tower collapse).","notable_events":["1968 M7.6 Casiguran earthquake (~270 casualties)"],"source":"Morante 1969; PHIVOLCS Destructive Earthquakes Catalog","geometry":[[122.3,16.4],[122.5,16.1],[122.7,15.8]]},{"slug":"tablas-lineament","name":"Tablas Lineament","type":"strike-slip","length_km":200,"region":"Romblon, Sibuyan Sea","description":"Offshore strike-slip lineament in the Sibuyan Sea linking the Mindoro and Masbate segments of the PFZ.","notable_events":["1948 M8.2 Lady Caycay (Panay) earthquake (regional context)"],"source":"PHIVOLCS Active Faults Map (2015)","geometry":[[121.7,13],[122,12.7],[122.3,12.4],[122.5,12.2]]},{"slug":"mindoro-fault","name":"Mindoro Fault (Aglubang River Fault)","type":"strike-slip","length_km":130,"region":"Oriental Mindoro","description":"Left-lateral strike-slip fault that ruptured during the 1994 M7.1 Mindoro earthquake. Surface rupture mapped along the Aglubang River valley.","notable_events":["1994 M7.1 Mindoro earthquake & tsunami"],"source":"Nakata et al. 1996","geometry":[[121,13.4],[121.2,13.3],[121.4,13.1],[121.6,13]]},{"slug":"tagaytay-makiling","name":"Macolod Corridor Faults","type":"strike-slip","length_km":80,"region":"Batangas, Laguna, Cavite","description":"NE-trending volcano-tectonic faults across the Macolod Corridor (Taal–Banahaw). Associated with frequent shallow swarms and Taal Volcano activity.","notable_events":["Recurrent shallow swarms around Taal Caldera"],"source":"Förster et al. 1990; PHIVOLCS","geometry":[[120.8,14.2],[121,14.05],[121.2,13.95],[121.5,13.9]]}]}